Process of manufacturing a composition containing matter of the character of caoutchouc



' Patented July 26, 1932 nitas amass PATENT OFFICE] rrnmnicrr ZIEGNER,or HAGEN, GERMANY PROCESS OF MANUFACTURINGA COMPOSITION CONTAININGMATTER OF THE CHARACTER OF CAOUTCHOU G I No Drawing. Application filedApril 1?, 1930, Serial No. 445,208, and in Germany April 25, 1929. i

My invention relates to improvements in the process of manufacturing acomposition containing matter of the character of caoutchouc, and moreparticularly in the process 5 in which a composition is made from matterof the character of caoutchouc and a suitable filling material such assaw dust, the said composition being suitable for example as asubstitute for linoleum. The object of the in improvements is to providea composition which contains a high proportion of filling material, andwith this object in View my invention consists in imbuingthe fillingmaterial such as saw dust with a suitablevliquid suchas gasoline adaptedto cause swelling of the caoutchouc, mixing the filling material thusimbued with caoutchouc, a vulcanizing medium, and other suitable matterto be described hereinater, allowing vaporization of the liquid, andvulcanizing the matter under pressure sufficient to close theinterstices prouced by vaporization of the liquid. I have found that bythus mixing the caoutchouc with the filling material having the saidswell- 9 ing liquid absorbed the caoutchouc is made to swell, so that avery high proportion of filling material may be mixed therewith. v

In my copending application for porous bodies and'the process ofmanufacturing the same, filed November 17, 1927, Ser. No. 234:,- 028, Ihave described a process of manufacturing a porous body from caoutchoucand a filling material adapted to absorb a liquid such as gasolinecapable of causing swell- 2 :3 ing of the caoutchouc, and my presentprocess is distinguished from the process described in the saidapplication in that high pressure is applied for closing the intersticesproduced by the evaporization of the gasoline, and that no water isadded to the mixture. I In a modification of the process Iv add asuitable softening medium such as paraifin to the caoutchouc, in orderto render the caoutchouc soft and fluent at elevated temperature, theresult being that the caoutchouc is more readily compacted atvulcanizingr temperature and under high pressure, and that it is moreintimately combined with the absorbing material.

When using the composition as a substitute filling media such as forlinoleum Iapply the same to a suitable backing preferably made fromfibre material.

In carrying out the process I may use the same ingredients whichareus'ed in the manufacture offthe porousfbod'y described in'the ,55

said prior application. Thus I use'a filling material in the form ofsmall particles or grains of porous material adapted to absorb theswelling medium, such for example as wood in the form of saw dust ormeal, pumice, and the like. As a binding medium connecting the grainsinto a coherent mass I use substances of the character of rubber suchfor example as rubber, gutta percha', or

balata intermingled if desired with the usual facticeychalk, orlithopone'; j i In the manufacture of the body I'proceed as followsr I i'lheporous grains are first imbued with a liquid such as gasolinecapable of swelling the binding medium, whereupon they are rapidly mixedwitha body of thecharacter of rubberhaving a suitable vulcanizingmedi-.um such as sulfur added thereto. In many 'zs cases the said rubber isused'in mixture with suitable filling matter such as lithopone, chalk orfactice. The grains and rubber are intermingled by known methods, forexample'bymeans of mixing rollers. I havefound that by first imbuing thegrains with gasoline I or the like the mass of grains which canbe addedto the rubber is largely increased as compared to aprocess inwhich thegrains are not imbued with gasoline, because vthe. gasoline partlydiffusinginto the rubber or the like causes the latterto swell, s0that'the amount of rubber needed for'co'ating' the surfaces of thegrains is considerably reduced as compared to the nonswollen rubber. Bydrying themixture the volatileswelling medium is vaporized, so that thebody of rubber or the like is contracted, and the filmsof rubber coatingthe grains are torn and' partly separated from the grains. After thusdrying thecomposition I subject the sameto vulcanization under highpressure, the pressure being sufficient to compact the'bodyand to closethe interstices. I have foundthat for this purpose a pressure of 15kilogrammes per square centimeter is sufiicient.

EwampZe.-To mixture of 100 parts. of rubber 7 parts of sulfur, 0,5 partsof an accelerator, 50 parts of lithopone, 75 parts of chalk, 200 partsof saw dust and 100 parts of gasoline are admixed on the rollers, theproduct being drawn out it desired on the calender into foils of anydesired thickness, which :toils may be applied under pressure to asuitable backing such as a fabric of jute. The foils are dried forexpelling the gasoline and vulcanized 4 hour in vulcanizing pressbetween plates heated to about 160 C. at a pressure of about 15kilogramn'ies per square centimeter.

In a modification of the process I add three parts of a suitablesoftening medium such as paratlin to this mixture in which case apressure of 8 kilogranuncs per square centimeter is sufficient.

The product has not the character of rubher, but it is similar in itsproperties to leather or linoleum.

I claim:

1. The herein described process of manufacturing compact bodies, whichconsists in imbuing porous particles of fibre material with a mediumadapted to swell matter of the character of rubber. intermingling thesaid porous particles with matter of the character of rubber and avulcanizing medium, causing vaporization of the said swelling medium,and vulcanizing under pressure sulficient to close the intersticescaused by the vaporization of the swelling medium.

2. The herein described process of manufacturing compact bodies, whichconsists in imbuing porous particles of fibre material with gasoline,intermingling the said porous particles with matter of the character ofrubher and a vulcanizing medium. causing vaporization of the saidgasoline, and vulcanizing under pressure suliicient to close theinterstices caused by the vaporization of the gasoline.

3. The herein described process of manufacturing compact bodies, whichconsists in iimbuing porous particles of fibre material with a. mediumadapted to swell matter of the character of rubber, intermingling thesaid porous particles with matter of the character of rubber, fillingmatter and a vulcanizing medium, causing vaporization of the saidswelling medium, and vulcanizing under pressure sufficient to close theinterstices caused by the vaporization of the swelling medium.

4. The herein described process of manufacturing compact bodies, whichconsists in imbuing porous particles of fibre material with a mediumadapted to swell rubber, intermingling the said porous particles withrubher and a vulcanizing medium, causing vaporization of the saidswelling medium, and

vulcanizing under pressure sufficient to close the interstices caused bythe vaporization of the swelling medium.

5. The herein described process of manufacturing compact bodies, whichconsists in imbuing porous particles of fibre material with a mediumadapted to swell matter of the character of rubber, intermingling thesaid porous particles with matter of the character of rubber, asoftening medium and a vulcanizing medium, causing vaporization of thesaid swelling medium, and vulcanizing under pressure sufficient to closethe interstices caused by the vaporization of the swelling medium.

6. The herein described process of manufactured compact bodies, whichconsists in imbuing porous particles of fibre material with a mediumadapted to swell matter of the character of rubber, intermingling thesaid porous particles with matter of the character of rubber, paratfinand a vulcanizing medium, causing vaporization of the said swellingmedium, and vulcanizing under pressure sutficient to close theinterstices caused by the vaporization of the swelling medium.

In testimony whereof I hereunto aflix my si nature.

HEINRICH ZIEGNER.

